GPS VMG Waypoint Circle Generator
March 5th, 2008 Posted in download, gps, hack, sailingThis Excel-based utility lets you set up a GPS receiver to calculate VMG (velocity made good) relative to a desired heading, to help you fine tune your sailing angles (choosing between pinching and footing upwind, and heating up vs. soaking downwind).
Essentially, this tool will generate a circle of waypoints centered around your sailing area, but several hundred miles away. By uploading these waypoints to your GPS receiver you enable “VMG relative to a heading” functionality, similar to what is available on the ultra-cool Velocitek SC-1. As long as your GPS receiver can calculate VMG to a waypoint, and you can upload waypoints to it from a “.gpx” file, you should be able to use this tool/hack to improve the sailing usefulness of your GPS.
Download: VMG_circle_waypoint_generator_B4.xls
(requires Microsoft Excel 2003 or later to run)
How does it work? Why is this better than simple VMG towards a mark? See the FAQ.
Screenshots:
Please note: while this tool allows you to configure your “standard” GPS to approximate the VMG functionality of a Velocitek SC-1, it is NOT meant to replace or compete with the Velocitek. If you use this tool/hack, and like the “VMG to a heading” functionality, you should consider upgrading to a Velocitek SC-1, which will give you “VMG to a heading” in a much easier to read display, plus many more useful features, and a more rapid refresh rate (2x per second, compared to most GPS receivers which only update 1x per second). Oh, and FYI… I have no relationship whatsoever to Velocitek. I just like their product!
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